Modified NiO-Ta2O5-based microwave dielectric ceramic material sintered at low temperature and its preparation method

Abstract

The invention belongs to the field of electronic ceramics and its manufacturing, in particular to the modified NiO—Ta 2 O 5 -based microwave dielectric ceramic material sintered at low temperature and its preparation method. It is guided by ion doping modification, not only considering the substitution of ions with similar radius, such as Zn 2+ replacing Ni 2+ ions, V 5+ replacing Ta 5+ ions; Meanwhile, the selected doped oxide still has the property of low melting point. Therefore, the microwave dielectric properties of NiO—Ta 2 O 5 -based ceramic material can be improved and the appropriate sintering temperature can be reduced. In the invention, by adjusting the molar content of each raw material, the NiO—Ta 2 O 5 -based ceramic material with low-temperature sintering, stable temperature and excellent microwave dielectric property is directly synthesized at one time, which can be widely applied to the technical field of LTCC.

What is claimed is: 
     
       1. A modified NiO—Ta 2 O 5 -based microwave dielectric ceramic material sintered at low temperature is characterized in that the general chemical formula of the modified NiO—Ta 2 O 5- -based microwave dielectric ceramic material sintered at low temperature is:
 (1.587y-0.198xy)ZnO-(2.597y-0.324xy)CuO-(1-x)NiO-(1.855y-0.231xy)B 2 O 3 -3xSnO 2 -(1-x)Ta 2 O 5 -(0.284y-0.035xy)V 2 O 5 ; wherein 0.1≤x≤0.2; 0.03≤y≤0.09; and prepared by solid-phase method; and the crystal type is NiTa 2 O 6  structure; 
 the sintering temperature of the microwave dielectric ceramic material is 875-950° C., and the microwave dielectric ceramic material is pre-sintered in the atmosphere environment of 850-900° C.; in addition, the dielectric constant is 17˜21, the quality factor Q×f value is 14,000˜23,000 GHz, and the temperature coefficient of resonance frequency is 5˜10 ppm/° C. 
 
     
     
       2. The modified NiO—Ta 2 O 5 -based microwave dielectric ceramic material sintered at low temperature according to  claim 1  is characterized in that when x=0.15 and y=0.06, the dielectric constant of the material is 20.2 at the sintering temperature of 925° C., the quality factor Q×f value is 22417 GHz, and the temperature coefficient of resonant frequency is 8.7 ppm/° C. 
     
     
       3. A preparation method of a modified NiO—Ta 2 O 5 -based microwave dielectric ceramic material sintered at low temperature is characterized in that it comprises the following steps:
 step 1, mixing ZnO, CuO, NiO, B 2 O 3 , SnO 2 , Ta 2 O 5  and V 2 O 5  powder according to the general chemical formula: (1.587y-0.198xy)ZnO-(2.597y-0.035xy)V 2 O 5 ;(x-0.10.2y-0.030.09), wherein 0.1≤x≤0.2; 0.03≤y≤0.09; 
 step 2, putting the powder mixed in step 1 into a ball milling tank, and performing ball milling with zirconia balls and deionized water according to a mass ratio of powder:zirconia balls:deionized water of 1:5-7:3-5, performing the planetary ball milling for 6-8 hours, taking it out, drying it in an oven at 80-120° C., sieving it with a 40-60 mesh sieve, and pre-sintering it in an atmosphere environment at 850-900° C. for 3˜5 hours; 
 step 3, performing ball milling on the powder pre-sintered in step 2 again according to a mass ratio of powder:zirconium balls:deionized water of 1:4-6:1-3, and performing planetary ball milling and mixing for 3-6 hours, taking it out and drying, and adding polyvinyl alcohol solution into the obtained powder for granulation; 
 step 4, pressing and molding the ceramic raw material prepared in step 3, discharging the glue at 600-650° C., and then sintering in the atmosphere environment at 875-950° C. for 4-6 hours to obtain the modified NiO—Ta 2 O 5 -based microwave dielectric ceramic material sintered at low temperature.